<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <link rel="stylesheet" href="index.css">
    <style>
        /* 布局展示样式，可删 */
        body {
            margin: 0;
            display: flex;
            justify-content: center;
            align-items: center;
            height: 100vh;
        }
    </style>
</head>
<body>
<div class="pyramid-loader">
    <div class="wrapper">
        <span class="side side1"></span>
        <span class="side side2"></span>
        <span class="side side3"></span>
        <span class="side side4"></span>
        <span class="shadow"></span>
    </div>
</div>
</body>
</html>